From the comment thread at Discover magazine (This post’s title comes from the same thread.):

Andrew recently resigned from being chair of the division, because he felt it was interfering with his family life… [H]e was in the process of putting his personal life back together. People who sat across from him at meeting tables the day before his death saw someone who was exhausted and distressed, but not hopeless. …[S]omething beyond Andrew’s control – perhaps something chemical – must have washed over him. It wouldn’t be the first time that an antidepressant has caused sudden suicidal thoughts.